1. Field of the Invention
This invention relates to energy management, and more particularly to an energy management device and an energy management method for a vehicle.
2. Description of the Related Art
U.S. Pat. No. 8,027,760 discloses a conventional energy management method for performing power management of an electric vehicle. The electric vehicle includes a supercapacitor, a battery and a plurality of energy loads (e.g., a motor, an air conditioner, etc.). According to the conventional energy management method, when the electric vehicle is located within a predetermined charging area relative to a charge station, the supercapacitor and the battery are charged by the charge station, and energy required by the energy loads is supplied by the charge station, and when the electric vehicle is located outside the charging area, the energy required by the energy loads is supplied by the supercapacitor first, and then by the battery once the residual electric quantity of the supercapacitor has decreased to its minimum value.
However, the conventional energy management method changes the source of the energy required by the energy loads from the charge station directly to the supercapacitor and from the supercapacitor directly to the battery, which results in relatively large temporary drops in input power of each of the energy loads, hindering smooth movement of the electric vehicle. Moreover, the conventional energy management method imposes no restriction on the discharge of the battery, which results in decrease of the lifetime of the battery.